1. Technical Field
The present invention relates to an ink jet method and an ink jet apparatus using the same.
2. Related Art
Because the ink jet method using ultraviolet-curable ink in which a monomer is photopolymerized (cured) through radiation of light is able to form an image with superior waterproofness and abrasion resistance on the recording surface of a recording medium, the method used in color filter manufacturing, in printing (recording) printed substrates, plastic cards, vinyl sheets, large scale signs, and plastic articles, and in printing bar codes or dates.
In order to stably supply the ultraviolet-curable ink from an ink cartridge to a head, it is advantageous to use a gear pump with little vibration. For example, JP-A-2012-20559 discloses a gear pump in which a gas permeable material is used in the components of the gear pump.
However, when ink passes through the gear pump, a problem arises of an ink polymerization reaction occurring in the gear pump due to the frictional heat of the gears in the gear pump, and the polymerization product fixing to and stopping the gears of the gear pump. The effect of suppressing the polymerization reaction of the ink composition in the gear pump by simply configuring the gear pump so that minute amounts of oxygen are incorporated using a gas permeable material in the components of the gear pump as in the apparatus disclosed in JP-A-2012-20559 is still insufficient.
In contrast, transporting the ultraviolet-curable ink composition using a tube pump or a diaphragm pump is also considered. In such methods, there is little fixing of the polymerization product. However, tube pumps have a problem of durability in that the tube is easily damaged. Because it is difficult for a diaphragm pump to transport liquids with a fixed flow rate, there are problems with discharge amount stability.